17,006 research outputs found

    Saliency Benchmarking Made Easy: Separating Models, Maps and Metrics

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    Dozens of new models on fixation prediction are published every year and compared on open benchmarks such as MIT300 and LSUN. However, progress in the field can be difficult to judge because models are compared using a variety of inconsistent metrics. Here we show that no single saliency map can perform well under all metrics. Instead, we propose a principled approach to solve the benchmarking problem by separating the notions of saliency models, maps and metrics. Inspired by Bayesian decision theory, we define a saliency model to be a probabilistic model of fixation density prediction and a saliency map to be a metric-specific prediction derived from the model density which maximizes the expected performance on that metric given the model density. We derive these optimal saliency maps for the most commonly used saliency metrics (AUC, sAUC, NSS, CC, SIM, KL-Div) and show that they can be computed analytically or approximated with high precision. We show that this leads to consistent rankings in all metrics and avoids the penalties of using one saliency map for all metrics. Our method allows researchers to have their model compete on many different metrics with state-of-the-art in those metrics: "good" models will perform well in all metrics.Comment: published at ECCV 201

    BORIS/CTCFL is an RNA-binding protein that associates with polysomes

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    © 2013 Ogunkolade et al.; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

    Genomic variations define divergence of water/wildlife-associated Campylobacter jejuni niche specialists from common clonal complexes

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    Although the major food-borne pathogen Campylobacter jejuni has been isolated from diverse animal, human and environmental sources, our knowledge of genomic diversity in C. jejuni is based exclusively on human or human food-chain-associated isolates. Studies employing multilocus sequence typing have indicated that some clonal complexes are more commonly associated with particular sources. Using comparative genomic hybridization on a collection of 80 isolates representing diverse sources and clonal complexes, we identified a separate clade comprising a group of water/wildlife isolates of C. jejuni with multilocus sequence types uncharacteristic of human food-chain-associated isolates. By genome sequencing one representative of this diverse group (C. jejuni 1336), and a representative of the bank-vole niche specialist ST-3704 (C. jejuni 414), we identified deletions of genomic regions normally carried by human food-chain-associated C. jejuni. Several of the deleted regions included genes implicated in chicken colonization or in virulence. Novel genomic insertions contributing to the accessory genomes of strains 1336 and 414 were identified. Comparative analysis using PCR assays indicated that novel regions were common but not ubiquitous among the water/wildlife group of isolates, indicating further genomic diversity among this group, whereas all ST-3704 isolates carried the same novel accessory regions. While strain 1336 was able to colonize chicks, strain 414 was not, suggesting that regions specifically absent from the genome of strain 414 may play an important role in this common route of Campylobacter infection of humans. We suggest that the genomic divergence observed constitutes evidence of adaptation leading to niche specialization

    Analysis of communication styles underpinning clinical decision-making in cancer multidisciplinary team meetings

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    INTRODUCTION: In cancer care, multidisciplinary team (MDT) meetings are the gold standard. While they are trying to maximize productivity on the back of the steadily increasing workload, growing cancer incidence, financial constraints, and staff shortages, concerns have been raised with regards to the quality of team output, as reported by Cancer Research UK in 2017: "Sometimes we discuss up to 70 patients. This is after a whole day of clinics, and we do not finish until after 19.00. Would you want to be number 70?". This study aimed to explore systematically some of the dynamics of group interaction and teamwork in MDT meetings. MATERIALS AND METHODS: This was a prospective observational study conducted across three MDTs/university hospitals in the United Kingdom. We video-recorded 30 weekly meetings where 822 patient cases were reviewed. A cross-section of the recordings was transcribed using the Jefferson notation system and analyzed using frequency counts (quantitative) and some principles of conversation analysis (qualitative). RESULTS: We found that, across teams, surgeons were the most frequent initiators and responders of interactional sequences, speaking on average 47% of the time during case discussions. Cancer nurse specialists and coordinators were the least frequent initiators, with the former speaking 4% of the time and the latter speaking 1% of the time. We also found that the meetings had high levels of interactivity, with an initiator-responder ratio of 1:1.63, meaning that for every sequence of interactions initiated, the initiator received more than a single response. Lastly, we found that verbal dysfluencies (laughter, interruptions, and incomplete sentences) were more common in the second half of meetings, where a 45% increase in their frequency was observed. DISCUSSION: Our findings highlight the importance of teamwork in planning MDT meetings, particularly with regard to Cancer Research UK in 2017 cognitive load/fatigue and decision-making, the hierarchy of clinical expertise, and the increased integration of patients' psychosocial information into MDT discussion and their perspectives. Utilizing a micro-level methodology, we highlight identifiable patterns of interaction among participants in MDT meetings and how these can be used to inform the optimization of teamwork

    Red flags presented in current low back pain guidelines: a review.

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    OBJECTIVE: The purpose of this study was to identify and descriptively compare the red flags endorsed in guidelines for the detection of serious pathology in patients presenting with low back pain to primary care. METHOD: We searched databases, the World Wide Web and contacted experts aiming to find the multidisciplinary clinical guideline in low back pain in primary care, and selected the most recent one per country. We extracted data on the number and type of red flags for identifying patients with higher likelihood of serious pathology. Furthermore, we extracted data on whether or not accuracy data (sensitivity/specificity, predictive values, etc.) were presented to support the endorsement of specific red flags. RESULTS: We found 21 discrete guidelines all published between 2000 and 2015. One guideline could not be retrieved and after selecting one guideline per country we included 16 guidelines in our analysis from 15 different countries and one for Europe as a whole. All guidelines focused on the management of patients with low back pain in a primary care or multidisciplinary care setting. Five guidelines presented red flags in general, i.e., not related to any specific disease. Overall, we found 46 discrete red flags related to the four main categories of serious pathology: malignancy, fracture, cauda equina syndrome and infection. The majority of guidelines presented two red flags for fracture ('major or significant trauma' and 'use of steroids or immunosuppressors') and two for malignancy ('history of cancer' and 'unintentional weight loss'). Most often pain at night or at rest was also considered as a red flag for various underlying pathologies. Eight guidelines based their choice of red flags on consensus or previous guidelines; five did not provide any reference to support the choice of red flags, three guidelines presented a reference in general, and data on diagnostic accuracy was rarely provided. CONCLUSION: A wide variety of red flags was presented in guidelines for low back pain, with a lack of consensus between guidelines for which red flags to endorse. Evidence for the accuracy of recommended red flags was lacking

    Load-Balancing for Parallel Delaunay Triangulations

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    Computing the Delaunay triangulation (DT) of a given point set in RD\mathbb{R}^D is one of the fundamental operations in computational geometry. Recently, Funke and Sanders (2017) presented a divide-and-conquer DT algorithm that merges two partial triangulations by re-triangulating a small subset of their vertices - the border vertices - and combining the three triangulations efficiently via parallel hash table lookups. The input point division should therefore yield roughly equal-sized partitions for good load-balancing and also result in a small number of border vertices for fast merging. In this paper, we present a novel divide-step based on partitioning the triangulation of a small sample of the input points. In experiments on synthetic and real-world data sets, we achieve nearly perfectly balanced partitions and small border triangulations. This almost cuts running time in half compared to non-data-sensitive division schemes on inputs exhibiting an exploitable underlying structure.Comment: Short version submitted to EuroPar 201

    A unified approach on Springer fibers in the hook, two-row and two-column cases

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    We consider the Springer fiber over a nilpotent endomorphism. Fix a Jordan basis and consider the standard torus relative to this. We deal with the problem to describe the flags fixed by the torus which belong to a given component of the Springer fiber. We solve the problem in the hook, two-row and two-column cases. We provide two main characterizations which are common to the three cases, and which involve dominance relations between Young diagrams and combinatorial algorithms. Then, for these three cases, we deduce topological properties of the components and their intersections.Comment: 42 page

    Adalimumab induced mononeuritis multiplex in a patient with refractory rheumatoid arthritis: a case report

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    which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background: Anti tumor necrosis factor agents are a valuable addition to the armamentarium against rheumatoid arthritis but have some serious side effects which clinicians should be aware about. Case presentation: We present a case of a 54 year old Caucasian male with refractory rheumatoid arthritis who developed mononeuritis multiplex four weeks after starting adalimumab therapy. Conclusion: Complete resolution of neurological and electromyography findings was seen upon stopping therapy. These agents can be a double-edged sword in the management of rheumatological illnesses. Though they help treat refractory disease, their potential side effects can include mononeuritis multiplex which can be recognized by means of clinical features, electromyography and nerve biopsy as depicted in our case. Background Anti tumor necrosis factor (TNF) agents are emerging i

    Anyons in a weakly interacting system

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    We describe a theoretical proposal for a system whose excitations are anyons with the exchange phase pi/4 and charge -e/2, but, remarkably, can be built by filling a set of single-particle states of essentially noninteracting electrons. The system consists of an artificially structured type-II superconducting film adjacent to a 2D electron gas in the integer quantum Hall regime with unit filling fraction. The proposal rests on the observation that a vacancy in an otherwise periodic vortex lattice in the superconductor creates a bound state in the 2DEG with total charge -e/2. A composite of this fractionally charged hole and the missing flux due to the vacancy behaves as an anyon. The proposed setup allows for manipulation of these anyons and could prove useful in various schemes for fault-tolerant topological quantum computation.Comment: 7 pages with 3 figures. For related work and info visit http://www.physics.ubc.ca/~fran

    Frequent burning promotes invasions of alien plants into a mesic African savanna

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    Fire is both inevitable and necessary for maintaining the structure and functioning of mesic savannas. Without disturbances such as fire and herbivory, tree cover can increase at the expense of grass cover and over time dominate mesic savannas. Consequently, repeated burning is widely used to suppress tree recruitment and control bush encroachment. However, the effect of regular burning on invasion by alien plant species is little understood. Here, vegetation data from a long-term fire experiment, which began in 1953 in a mesic Zimbabwean savanna, were used to test whether the frequency of burning promoted alien plant invasion. The fire treatments consisted of late season fires, lit at 1-, 2-, 3-, and 4-year intervals, and these regularly burnt plots were compared with unburnt plots. Results show that over half a century of frequent burning promoted the invasion by alien plants relative to areas where fire was excluded. More alien plant species became established in plots that had a higher frequency of burning. The proportion of alien species in the species assemblage was highest in the annually burnt plots followed by plots burnt biennially. Alien plant invasion was lowest in plots protected from fire but did not differ significantly between plots burnt triennially and quadrennially. Further, the abundance of five alien forbs increased significantly as the interval (in years) between fires became shorter. On average, the density of these alien forbs in annually burnt plots was at least ten times as high as the density of unburnt plots. Plant diversity was also altered by long-term burning. Total plant species richness was significantly lower in the unburnt plots compared to regularly burnt plots. These findings suggest that frequent burning of mesic savannas enhances invasion by alien plants, with short intervals between fires favouring alien forbs. Therefore, reducing the frequency of burning may be a key to minimising the risk of alien plant spread into mesic savannas, which is important because invasive plants pose a threat to native biodiversity and may alter savanna functioning
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